1. Field of the Invention
This invention relates to non-linear oscillator using electronically conducting polymer films and sensor employing such oscillators.
2. Description of the Related Art
Recently, the role of non-linear oscillators in information processing mechanisms of organisms has been attracting attention. The inventors conducted biological information processing research and investigations using slugs and clearly that non-linear oscillations of local field potentials in procerebral lobe are closely related to the learning and memory of odor information. When applications of the phenomenon of non-linear oscillations (to biological sensors, for instance) is considered, it is most important to develop a stable non-linear oscillator. However, well-known non-linear oscillations such as those of BZ reaction, oil-water interface reaction, phase transition reaction of lipids, etc. are basically produced under non-equilibrium systems by mass transport. Therefore, it is inherently difficult to obtain stable oscillations, and applications thereof are limited.
Meanwhile, there has been recent research concerning polypyrrole and similar conducting polymers capable of oxidation and reduction and having ion selectivity, and applications of such polymers using special film properties thereof have been investigated. Kotowski et al. reports (J. Kotowski, T. Janas and H. T. Tien, Bioelectrochem. Bieonerg., 19(1988)283) that interesting electrical oscillations were obtained in composite membrane systems of bilayer membranes comprising polypyrrole and lipid. With this report as a reference, the inventors conducted research and investigations with the aim of obtaining stable electric oscillations with films of only polypyrrole to obtain aperiodic membrane potential oscillations via a polypyrrole only film (M. Iseki, M. Ikematsu, Y. Sugiyama and A. Mizukami, Bioelectrichem. Bioenerg., 34(1994)149).